Definition
Complaint carries distinct meanings in civil and criminal law, though both share a common core: a formal presentation of a grievance or charge to a legal authority.
1. CIVIL PROCEDURE. In code-pleading jurisdictions, the complaint is the first pleading filed by a plaintiff, initiating a civil action. It sets out the facts forming the basis of the plaintiff's claim, identifies the parties, states the relief sought, and establishes the court's jurisdiction. In function it corresponds to the declaration under common-law pleading. The complaint triggers the defendant's obligation to respond and defines the boundaries of the dispute.
2. CRIMINAL LAW. In criminal procedure, a complaint is a formal charge or accusation made before a magistrate or other authorized officer, alleging that a named or identifiable person has committed a specified offense. It is typically supported by oath and constitutes the initiatory step in a criminal prosecution or magistrate's examination. A complaint is a preliminary instrument — it is distinct from an indictment or information, which are the charging documents used at the stage of formal prosecution.
3. ADMINISTRATIVE AND REGULATORY CONTEXTS. Complaint is also used broadly in administrative proceedings to describe a formal allegation initiating an agency inquiry or adjudicatory process, though the procedural specifics vary by jurisdiction and regulatory scheme.
Common Language
Modern common usage (Wiktionary): The act of complaining; a grievance, problem, difficulty, or concern; a bodily disorder or disease; the symptom of such a disorder.
Historical common usage (Webster's 1913): Expression of grief, regret, pain, censure, or resentment; lamentation; murmuring; accusation; fault-finding; an ailment or disease of the body.
In ordinary English, a complaint is informal — an expression of dissatisfaction requiring no particular form, recipient, or consequence. The legal complaint is a term of art: a formal written instrument filed with a court or officer, subject to procedural rules, capable of conferring or triggering jurisdiction, and bearing legal consequences if deficient. The overlap in vocabulary conceals a complete difference in formality and effect.
Common Confusion
COMPLAINT VS. DECLARATION VS. INDICTMENT
In common-law pleading jurisdictions, the first civil pleading was the declaration, not the complaint. Code-pleading states replaced "declaration" with "complaint," and federal practice under the Federal Rules of Civil Procedure uses "complaint" throughout. Researchers working in pre-code materials or common-law jurisdictions should search under declaration rather than complaint for equivalent instruments. In criminal law, a complaint initiates proceedings before a magistrate; an indictment or information is the charging instrument for trial. The two are not interchangeable, and historical sources sometimes use accusation, charge, or information loosely as near-synonyms where precise meaning differs.
Core Elements
CIVIL COMPLAINT
(1) Identification of the parties and court
(2) A statement of the facts constituting the cause of action
(3) The legal basis for relief
(4) A demand for judgment or specific remedy
CRIMINAL COMPLAINT
(1) An accusation of a designated offense
(2) Identification of the alleged offender (or description if unknown)
(3) Support by oath or affirmation
(4) Presentation to a magistrate or officer of competent jurisdiction
(5) An implicit or explicit request that the offender be examined or charged
Why It Matters in Research
The civil and criminal meanings of complaint operate under entirely different procedural regimes, and historical sources do not always clearly signal which they are discussing. Researchers should verify the procedural context before applying any definition.
For civil research, the pivotal divide is code pleading versus common-law pleading. Historical materials from before a jurisdiction's adoption of a civil procedure code will use declaration where modern materials use complaint. New York's Code of Civil Procedure (1848) is the landmark reform; many states followed in subsequent decades. Federal materials conform to the Federal Rules of Civil Procedure (1938), which uniformly use complaint. Pre-1938 federal civil practice also used declaration in some contexts.
The well-pleaded complaint rule is a critical doctrine for federal jurisdiction research. Federal question jurisdiction under 28 U.S.C. § 1331 is determined solely by what appears on the face of the plaintiff's complaint — not by anticipated defenses or counterclaims. This rule governs which cases belong in federal court and has substantial implications for removal and jurisdictional analysis. The Law Mind Civil Procedure & Evidence Encyclopedia entry on Federal Question Jurisdiction addresses this directly.
For criminal research, the complaint's role is specifically pre-indictment and magistrate-level. Researchers tracing criminal proceedings in historical sources should not treat complaint and indictment as equivalent. In federal practice and most states, the complaint initiates arrest or preliminary hearing; the grand jury indictment or prosecutor's information carries the case to trial. Some historical sources use complaint loosely to encompass both stages — Anderson's Dictionary notably observes that complaint "may include an indictment," which reflects a broader colloquial usage that most modern practice has abandoned.
Burrill's citation of the Latin querela is a useful cross-reference for researchers working in older English, ecclesiastical, or civil-law materials, where querela denotes a formal complaint or action.
Historical Dictionary Support
The historical dictionaries converge on the civil/criminal bifurcation but differ in emphasis and precision.
Black's (1st Ed.) focuses primarily on the civil complaint under code practice, anchoring its definition to New York's Code of Civil Procedure and providing the standard four-part content requirement. This reflects the code-pleading reform movement that was reshaping American civil procedure at the time of Black's compilation. Bouvier's, by contrast, leads with the criminal meaning — the allegation before a magistrate — and treats the civil meaning as secondary. This ordering likely reflects Bouvier's earlier vintage and its greater attention to criminal and common-law procedure.
Rapalje & Lawrence presents both meanings in numbered sequence without privileging either, a structure that serves the researcher well. Anderson's offers the most expansive criminal definition, emphasizing that a complaint is the "initial proceeding in criminal prosecutions" and noting that it implies oath. Anderson's aside that complaint may include an indictment is the outlier among these sources; it likely reflects usage in jurisdictions where the formal distinction between preliminary complaint and charging indictment had not yet been sharpened procedurally.
Burrill's contributes the Roman law antecedent (querela) and frames the concept at its most abstract: "representation of facts constituting a supposed injury or offence, to a court or officer having jurisdiction." This formulation is useful for understanding complaint as a genus, of which civil and criminal complaints are species.
The second edition of Black's entry provided in the source material does not address complaint directly (the excerpt concerns compiled statutes), suggesting the second edition material here is a compilation artifact rather than a substantive complaint entry.
Jurisdictional Note
Federal practice under the Federal Rules of Civil Procedure uses complaint universally for the plaintiff's initial civil pleading. State practice largely mirrors this, though some states retain older nomenclature in specialized courts. In criminal matters, federal practice under the Federal Rules of Criminal Procedure uses complaint specifically for the pre-indictment charging instrument before a magistrate judge; this usage is precise and not interchangeable with indictment or information.
Encyclopedia Cross-Reference
Federal Question Jurisdiction — 28 U.S.C. § 1331 and the Well-Pleaded Complaint Rule (The Law Mind Civil Procedure & Evidence Encyclopedia)